package handlers

import (
	"io/fs"
	"net/http"
	"strings"

	"sneak.berlin/go/dnswatcher/static"
)

// HandleStatic returns the handler for the embedded static assets. It
// is mounted under /s, with that prefix stripped from the path. A
// request that names a directory answers 404: http.FileServer would
// answer it with a listing of the directory, or with a redirect to
// that listing when the trailing slash is missing.
func (h *Handlers) HandleStatic() http.HandlerFunc {
	files := http.FileServer(http.FS(static.Static))

	return func(
		writer http.ResponseWriter,
		request *http.Request,
	) {
		// fs.Stat refuses a name that is empty or ends in a slash,
		// so /s/ and /s/css/ answer 404 here along with /s/css.
		name := strings.TrimPrefix(request.URL.Path, "/")

		info, err := fs.Stat(static.Static, name)
		if err != nil || info.IsDir() {
			http.NotFound(writer, request)

			return
		}

		files.ServeHTTP(writer, request)
	}
}